Not a bad night for Alex Smith, and it could have been better, considering that the one incomplete pass was dropped by a wide-open receiver.

The San Francisco quarterback completed 18 of 19 passes for 232 yards and three touchdowns — two to Michael Crabtree and one to Randy Moss — to help San Francisco flatten the Arizona Cardinals 24-3 on Monday night.

"Eighteen of 19, I have never seen that," 49ers coach Jim Harbaugh said. "How important for your quarterback to play very well? It is very important and I don't know how you play much better. It was a fantastic game by him."

"Everyone's surprised. My 5-year-old son's surprised," Dockett said, "but at the end of the day it wasn't like he had to make the long perfect throws. He had some guys open and we missed some tackles and they made plays."

Smith said he had no idea his stats were that good.

"Which is a good thing," he said. "I don't want to think about my stats or incompletions or anything like that. I was kind of in a good rhythm, the whole offense was. "

Smith has withstood more than his share of criticism he was the No. 1 overall pick in the draft in 2005. He was not interested in calling this a statement performance.

"At this point I don't care," he said. "if you ask me a few years ago, yeah maybe, but at this point I don't really care. I am concerned about winning. The guys in the locker room know what I am about and that is what really matters."

Smith was 14 of 15 for 146 yards and two touchdowns, both to Crabtree, as the 49ers built a 17-0 halftime lead.

Moss caught a 47-yard TD pass, dodging tacklers down the sideline on a play that seemed to turn back the clock to the receiver's prime. With the catch, he tied Terrell Owens for fourth on the NFL career touchdown list with 156.

Smith, who tied a career high with the three touchdown passes, spread out his completions to 10 receivers. Crabtree led the way with five catches for 72 yards.

Arizona's defense, supposed to be the team's strength, missed tackle after tackle in an embarrassing nationally televised performance at home. The 24 points were the most allowed by the Cardinals this season.

"This was a big test for us, and everyone saw how it went," Arizona coach Ken Whisenhunt said. "It was disappointing to say the least."

Quarterback John Skelton called the loss "embarrassing" and "humiliating."

Led by Smith's near-perfect precision passing, the 49ers methodically dominated from the start. He had the best completion percentage of his career, and he would have been perfect had Delanie Walker not dropped the ball when he was wide open on a crossing route in the first half.

A 10-play, 77-yard drive that consumed just over 6 minutes of the first quarter put San Francisco up 7-0. On third-and-goal from the 3, Smith threw a sidelines pass to Crabtree, who outfought Patrick Peterson for the ball and the touchdown.

A flurry missed tackles, most notably an open-field whiff by Sam Acho, helped Ted Ginn Jr. return a punt 35 yards to the Arizona 45 in the second quarter. Daryl Washington sacked Smith to help set up a third-and-23 from the Arizona 46. But Smith found Crabtree over the middle for 22 yards, just a yard shy of the first down. David Akers' 43 yard field goal made it 10-0 with 5:58 left in the half.

Crabtree beat Peterson again for San Francisco's second touchdown. Smith threw over the middle to the receiver, who caught the ball, then fooled Peterson with an inside move into the end zone to make it 17-0 with 1:41 left in the half. The 49ers drove 68 yards in eight plays, again overcoming a sack, this one by Calais Campbell, that made it second-and-goal from the 16. Smith threw 7 yards to Mario Manningham to set up the TD toss to Crabtree.

The Cardinals were booed off the field by the home crowd at the half.

Things didn't get any better for the home team in the third quarter. On third-and-9, Smith threw 30 yards to Crabtree, who evaded a host of tacklers. Then on third-and-8, Smith tossed a short pass to Moss, who sidestepped a series of would-be defenders all the way to the end zone, putting San Francisco ahead 24-0 with 7:27 left in the third quarter.

The Cardinals averted a shutout with Jay Feely's 28-yard field goal

John Skelton, making his second start since Kevin Kolb went down with rib injuries, completed 32 of 52 passes for 290 yards, often overthrowing receivers. The Cardinals rushed for just 7 yards in nine attempts against the 49ers, who entered the game as the No. 1-ranked defense in the NFL, No. 2 against the run.

Arizona's final possession ended when Larry Fitzgerald was stopped at the 1.